Here are entered compositions not in a specific form or of a specific type for piano, violin, viola and cello.Compositions not in a specific form or or a specific type for piano and three other solo instruments are entered under Quartets followed by medium of performance, e.g. Quartets (Piano, violins (2), cello). --headings for forms and types of music that include "piano quartet" and headings for medium of performance that include "piano quartet"